I have a similar request based on a similar purpose.
Many many cards, but sometimes I want a complete overview what I own, sometimes only a list of one single location, like what is in one deck or one binder or box.
So I saw myself deciding between storage models: One single collection with everything or multi-collection, one per location.
Examples: I have about 20 Mishras factory.
First question: How many Mishras do I have exactly in total? This can be solved with single collection model only.
Second question: Where exactly is that heavily played 4th Edition one that I want to replace? This can be solved with multi-collection model only.
I decided for the multiple collections and exported all of them into one common spreadsheet. But everytime you change one collection, the spreadsheet outdates.
So I asked in this forum for a one-click bulk export of all collections, but no success.
Sub-collections or a location attribute for a card in a collection or the like would also fulfil my purpose I guess...